I figured out why I am emotional when I leave. It's three-fold.

The first reason is that I am slightly depressed due to other factors in my life, such as finding a roommate and possibly paying the entire rent on my own. I am totally secure in my job though so at least I don't have to worry about that. But yes I am stressed about finances and how I am going to pay for things and accomplish my goals and deal with life. I just got out on my own a few months ago. So when I am stressed out, anxious, and depressed, it makes me more emotional.

The second reason is that I need to see him twice a week instead of once a week.

And thirdly, "goodbyes" are an emotional button for me anyway.

No, I do not love him "sooooooooooooooooooooooooo" much, and no I do not think for one minute that he would cheat on me or date another woman.

Posting here helped me figure all this out. Thank you everyone for responding!